#region Copyright notice and license

// Copyright 2018 gRPC authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#endregion

using System;
using System.Diagnostics;
using Grpc.Core.Utils;

namespace Grpc.Core.Interceptors;

/// <summary>
/// Decorates an underlying <see cref="Grpc.Core.CallInvoker" /> to
/// intercept calls through a given interceptor.
/// </summary>
[DebuggerDisplay("{invoker}")]
internal class InterceptingCallInvoker : CallInvoker
{
    readonly CallInvoker invoker;
    readonly Interceptor interceptor;

    /// <summary>
    /// Creates a new instance of <see cref="Grpc.Core.Interceptors.InterceptingCallInvoker" />
    /// with the given underlying invoker and interceptor instances.
    /// </summary>
    public InterceptingCallInvoker(CallInvoker invoker, Interceptor interceptor)
    {
        this.invoker = GrpcPreconditions.CheckNotNull(invoker, nameof(invoker));
        this.interceptor = GrpcPreconditions.CheckNotNull(interceptor, nameof(interceptor));
    }

    /// <summary>
    /// Intercepts a simple blocking call with the registered interceptor.
    /// </summary>
    public override TResponse BlockingUnaryCall<TRequest, TResponse>(Method<TRequest, TResponse> method, string? host, CallOptions options, TRequest request)
    {
        return interceptor.BlockingUnaryCall(
            request,
            new ClientInterceptorContext<TRequest, TResponse>(method, host, options),
            (req, ctx) => invoker.BlockingUnaryCall(ctx.Method, ctx.Host, ctx.Options, req));
    }

    /// <summary>
    /// Intercepts a simple asynchronous call with the registered interceptor.
    /// </summary>
    public override AsyncUnaryCall<TResponse> AsyncUnaryCall<TRequest, TResponse>(Method<TRequest, TResponse> method, string? host, CallOptions options, TRequest request)
    {
        return interceptor.AsyncUnaryCall(
            request,
            new ClientInterceptorContext<TRequest, TResponse>(method, host, options),
            (req, ctx) => invoker.AsyncUnaryCall(ctx.Method, ctx.Host, ctx.Options, req));
    }

    /// <summary>
    /// Intercepts an asynchronous server streaming call with the registered interceptor.
    /// </summary>
    public override AsyncServerStreamingCall<TResponse> AsyncServerStreamingCall<TRequest, TResponse>(Method<TRequest, TResponse> method, string? host, CallOptions options, TRequest request)
    {
        return interceptor.AsyncServerStreamingCall(
            request,
            new ClientInterceptorContext<TRequest, TResponse>(method, host, options),
            (req, ctx) => invoker.AsyncServerStreamingCall(ctx.Method, ctx.Host, ctx.Options, req));
    }

    /// <summary>
    /// Intercepts an asynchronous client streaming call with the registered interceptor.
    /// </summary>
    public override AsyncClientStreamingCall<TRequest, TResponse> AsyncClientStreamingCall<TRequest, TResponse>(Method<TRequest, TResponse> method, string? host, CallOptions options)
    {
        return interceptor.AsyncClientStreamingCall(
            new ClientInterceptorContext<TRequest, TResponse>(method, host, options),
            ctx => invoker.AsyncClientStreamingCall(ctx.Method, ctx.Host, ctx.Options));
    }

    /// <summary>
    /// Intercepts an asynchronous duplex streaming call with the registered interceptor.
    /// </summary>
    public override AsyncDuplexStreamingCall<TRequest, TResponse> AsyncDuplexStreamingCall<TRequest, TResponse>(Method<TRequest, TResponse> method, string? host, CallOptions options)
    {
        return interceptor.AsyncDuplexStreamingCall(
            new ClientInterceptorContext<TRequest, TResponse>(method, host, options),
            ctx => invoker.AsyncDuplexStreamingCall(ctx.Method, ctx.Host, ctx.Options));
    }
}
